High-pressure boiler having a large heating surface and particularly adapted for locomotives



Dec. 19, 1933. NYFFE GGER 1,939,787

HIGH sURR BOILER HAVIN LARGE HEATING SURFACE PARTICULARLY ADAPTED FOR LOCOMOTIVES Filed Jan. 4,

Patented Dec. 19, 1933 PATENT OFFICE.

HIGH-PRESSURE BOILER HAVING A LARGE HEATING SURFACE AND PARTICULARLY ADAP'IED FOR LOCOMOTIVES Hans Nyfleneg ger, Winterthur, Switzerland, as-

signor to firm Schweizerische Lokomotivund 1 Maschinenfabrik, Winterthur, Switzerland Application January 4, 1933, Serial No. 650,196, and in Germany January 8, 1932 '1 Claim. (Cl. 122-235) This invention relates to high pressure boilers having a large heating'surface and particularly adapted for locomotives.

With high pressure water tube boilers particularly for locomotives, it is known,"to arrange the .water tubes in fork-shaped evaporating elements that-are transversely disposed to the longitudinal axis of the upper steam collecting drum (Fig. 1) in such manner that they ascend from two lower drums extending laterally. of the grate, so that the entity of the watertubes form the two side walls of the the box andthe ,fire box ceiling which protects the upper drumfrombeing heated. The steam generated in every one of the evaporating elements succeeding each other in the longitudinal direction of the boiler is led into the upper drums through a short pipe connection which is welded on to the portion of the element forming the ceiling of the fire box and beaded on to the upper drums.

This arrangement for the evaporating elements provides with the usual pipe dimensions a construction which is adapted to practically compensate the expansions due to heat arising during the operation (which is always the case), so

that with different temperatures existing between the drum system, (particularly the supports therefor) and the system of the water or evaporating tubes no detrimental stresses caused by the heat expansions occur. However, the following points must be considered. Owing to the fact that the vertical pipe connections arranged,

in. the horizontal part of the U-shaped pipes are positioned laterally off the centre of the pipe, for the purpose, of providing that the places where the tubes are beaded onto the upper drum are situated on different sides of the longitudinal middle plane of the upper boiler, by an alternate arrangement, the legs of the water tubes are of unequal lengths, whereby dangerous stresses due to heat particularly in the vertical pipe connections on the upper drum arise. When the evaporating elements are made in two pieces of a pipe each of which is separately connected to the upper drum (Fig. 3) the stresses due to heat are practically eliminated which permits of forming the evaporating elements, in the simplest manner, only by bending and without weldincluding only one upper drum (Fig. 1) each evaporating tube was to be connected by a separate pipe connection to the upper drums, (Fig. 2). The horizontal portion of the evaporating elements provides also here effective protection 0 for the upper drums against heating up, but the portion of the upper drums disposed between the pipe connections may cause extremely dangerous stresses duetoheat, particularly in the pipe connections, when difierences in the tem- 5 peratures of the system of carriers for the drums and, the water tubes occur. These stresses may be, avoided by providin pipe connections of longer lengths, but with the undesirable consequence thatthe height of o the 7 side walls of the fire box is decreased and a very valuable amount of heating surface is lost. A further disadvantage of the said disposition is that the content in the tubes of the ceiling between the two educting connections and the up- 7 per drums may be caused to stagnate even with higher outputs of the boiler, wherefrom dangerous overloading of the boiler may accrue. On the other hand, also from the point of view of manufacturing the boiler this kind of connection 30 to the upper and the lower drums is undesirable.

According to the present invention, the lower drums are alternately connected at each evaporating element with one of the upper drums.

In this manner a continuous ceiling for protecting the upper drums against being heated is formed the small interruptions of which arising between the educting connections can easily be filled out with any suitable fire-proof mass.

This construction may, in a similar manner, also be applied to boilers comprising three or more upper drums.

In the accompanying drawing a constructional form of the invention is schematically illustrated together with several known constructions, in which Fig. 1 represents a cross section of a boiler of a known construction comprising one upper drum and forked evaporating elements;

Fig. 2 is a cross section of a boiler including 101 two upper drums and forked evaporating elements,

Fig. 3 is a cross section of a boiler comprising one upper drum and bipartite evaporating elements, and 105 Fig. 4 depicts a cross section of a boiler having two upper drums and bipartite evaporating elements.

Referring to Fig. 1 of the drawing, for a known arrangement, an upper drum a is connected 11G with the lower drums b, b through a forked evaporating element 0 by means of a pipe connection d.

In Fig. 2, which shows another known arrangement two upper drums a, a are illmiirated which are connected with the lower drums b, b through a forked evaporating element awhich is provided with two pipe connections 01, d. f and d, (1 denote the parts of the evaporating element e which are subjected to pmti'nrrlarly dangerous stresses due to heat;

In Fig. 3, showing still another known arrange ment, an upper drum a communicates with a lower drum b by an evaporating tube 9 and with the lower drum 2) by a tnbegf. The tubes; g and g lie in the same transverse plane and constitute conjointly one of the elements.

Fig. 4 illustrates an arrangement mozdmg to the present invention. By a, a two upper drums are designated alternatliy mm; mieate with two lower drums b, b-'..' For this purpose the upper drum a isconnected by the water or evaporating tubes 9, 9" the lower drums F, b andtheupper drum w more lower drums: b; b by the tubes h,h"1oeming the next succeeding evaporating element 1': rs the Trent and wall of the tire box.

' In oirder'te prevent undue stressing 'ot the er the upper the tubes 9' and? k, h are with time upper drums alternately on the right hand of the duties! longitudinal planes extending through the centreof the upper and our the left hand side otthese'planes.

I do not limit myself to the particular size, shape, number or arrangement of parts as shown and described, all of which may be varied without going beyond the scope of my invention as described and chimed.

What I claim is:

In a; high-pressure boiler of the type described, incombination two lower water drums, at least two upper steam collecting drums, a fire box sail drums, evaporating tubes extending in pairs of correlated branches from said lower drums to said upper drums in transverse planes perpendicularly disposed to the longamma: mkldle; plane of the boiler, said branches having vertical portions conjointly constituting the side walls of said fire box and having substantially horizontal portions constituting the ceiling of said fire box for protecting said upper drums against radiating heat from said fire box, said horizontal portions extending with their ench with only Ismail interstice between some, for rendering heat protectionby said ceiling effective tm'uugheu t the: of the ceiling, separate connections on said adjacent emls of horizontal portions: of said 10 of evaporating tubebranel'ies extendingup to said upper drums withal-temate pairs of eon-elated pipe connections arranged on a fer ent upper In the various transverse planes, and a.- l'ower pipe connection on each bran-ch tube extending down to the correlated le-werdrum in substantiell-y parallel relationto the upper pipe of the respective branch tube. Y I

HANS H0 

